t/201-fail: add a simple test for non-existent source files.
t/201-fail: add a simple test for non-existent source files.

(This actually went uncaught in my redo rewrite.  Oops.)

dinkelk/redo-python,rowhit/redo,pombredanne/redo,apenwarr/redo,pombredanne/redo,dinkelk/redo-python,apenwarr/redo,rowhit/redo,dinkelk/redo-python,apenwarr/redo,pombredanne/redo,apenwarr/redo,dinkelk/redo-python,pombredanne/redo,rowhit/redo,rowhit/redo